Preparation of Loess-Clay Based Eco-Friendly Geopolymer for Efficient Removal of Pollutants in Water

Abstract

Heavy metals and dyes cause serious harm for water environment, geopolymer materials with the large pores and specific surface area, and easy modification of pore surface have received extensive attention in wastewater treatment. Herein, using loess-clay (LC) as natural mineral materials, we developed an eco-friendly geopolymer of loess-clay (GpLC) with excellent adsorption properties and promotion plant growth was prepared by alkali excitement. Its morphology and structure were exhibited by scanning electron microscopy, Fourier transform infrared spectroscopy, XRD, and Brunauer–Emmett–Teller. Moreover, its adsorption property for removing metal ions and different dyes was measured, and the adsorption kinetics and thermodynamics were investigated. GpLC presented excellent adsorption ability for Pb²⁺, which the removal rate got to 98.7 %. It had the universality of removing organic pollutants, and the removal rate reached to 98.0 %. It was dominated chemisorption and single-layer adsorption, which GpLC conformed to quasi-second-order adsorption kinetics, and being more consistent with Langmuir isothermal model. Furthermore, it was found that GpLC could promote growth of crops as it contain P and K element with essential element of plants. In summary, it provides insights and strategy for developing a kind of eco-friendly functional materials with strong adsorption capacity and promoting plant growth, and it is an effective method for reusing loess resources.